They were rescued at 02:00 local time on Sunday and flown to University Medical Center in Las Vegas, Nevada, a statement said.

‘Extremely rugged’

The chief of the local Hualapai Police, Francis Bradley, called the incident “very tragic”.

He added: “Yesterday, we were hampered by severe weather conditions [and] we had gusts up to 50mph [80kmph].”

He said the terrain around the crash site was also “extremely rugged”.

A UK Foreign Office spokesperson said: “We are providing support to the families of six British visitors involved in a helicopter accident at the Grand Canyon on 10 February, and we are in close contact with the US emergency services.”

In a statement, Brenda Halvorson, the chief executive of the helicopter company involved – Papillon Airways – said the company extended its heartfelt sympathy to the families of the dead and injured.

On its website, Papillon calls itself “the world’s largest aerial sightseeing company” and says it flies more than 600,000 people a year.

The Grand Canyon, which is more than 1.6km (one mile) deep, is one of the most visited tourist attractions in the US.